: I did a search here on this, but didn't find
: the answers I was looking for.
: Here's the setup: My new "Screamin'
: Six" engine, 450 Holley mechanical
: secondary, #66 jets in the primaries and a
: #67 jet equivalent metering plate (#9) in
: the secondaries. Carb is on an Offenhauser
: aluminum intake, mounted front to rear, with
: the throttle linkage on the drivers' side,
: just like a stock BBD. MP 268 cam (runs
: nice, not too much for a street engine) with
: 18/23 hot lash. Autolite 26 plugs. MEASURED
: and CC'D 9.04:1 compression ratio, with
: compression test numbers all between 190-200
: psi.
:
: Here's what the plugs looked like, both for the
: side electrode and insulator. I had the PCV
: routed to manifold vaccum, but after I saw
: #6 plug, I rerouted it to the air cleaner.
:
: #1. Ins.-brown , elec.-black
: #2. Ins.-brown/tan , elec.-brown
: #3. Ins.-tan , elec.-brown/black
: #4. Ins.-white , elec.-tan
: #5. Ins.-white , elec.-tan
: #6. Ins.-black , elec.-black
:
: Like I said, I think the PCV fumes are what
: made #6 so black. Plug gap was 40 with a
: stock electronic ignition, and I closed it
: down to 35 after cleaning the plugs.
: What would be a good Champion plug to use?
: Remember that this 1979 head uses the
: 5/8" hex tapered seat plugs.
: Any ideas on using different heat range plugs
: in different cylinders?
: I think some manifold modifications are needed
: here, because the primaries are naturally
: closer to the front 3 cylinders.
: The electrode on #1 was a "medium
: black", but on #6 it was "black
: black".
: What to do?

: I did a search here on this, but didn't find
: the answers I was looking for.
: Here's the setup: My new "Screamin'
: Six" engine, 450 Holley mechanical
: secondary, #66 jets in the primaries and a
: #67 jet equivalent metering plate (#9) in
: the secondaries. Carb is on an Offenhauser
: aluminum intake, mounted front to rear, with
: the throttle linkage on the drivers' side,
: just like a stock BBD. MP 268 cam (runs
: nice, not too much for a street engine) with
: 18/23 hot lash. Autolite 26 plugs. MEASURED
: and CC'D 9.04:1 compression ratio, with
: compression test numbers all between 190-200
: psi.
:
: Here's what the plugs looked like, both for the
: side electrode and insulator. I had the PCV
: routed to manifold vaccum, but after I saw
: #6 plug, I rerouted it to the air cleaner.
:
: #1. Ins.-brown , elec.-black
: #2. Ins.-brown/tan , elec.-brown
: #3. Ins.-tan , elec.-brown/black
: #4. Ins.-white , elec.-tan
: #5. Ins.-white , elec.-tan
: #6. Ins.-black , elec.-black
:
: Like I said, I think the PCV fumes are what
: made #6 so black. Plug gap was 40 with a
: stock electronic ignition, and I closed it
: down to 35 after cleaning the plugs.
: What would be a good Champion plug to use?
: Remember that this 1979 head uses the
: 5/8" hex tapered seat plugs.
: Any ideas on using different heat range plugs
: in different cylinders?
: I think some manifold modifications are needed
: here, because the primaries are naturally
: closer to the front 3 cylinders.
: The electrode on #1 was a "medium
: black", but on #6 it was "black
: black".
: What to do?

: Good review Tim,
: This is about what I would expect, on a SL6,
: the end cylinders can run rich from the
: "boundry effect" where liquid fuel
: will collect on the outer walls of the
: manifold (out at the
: "boundries")then run along that
: wall into what ever cylinder it leads to.
:
: You already have some good plans, you should: *
: re-route the PCV air into the main plentum
: area, hopefully towards the front 3
: cylinders
: * try some hotter plugs in the end cylinders
: * lean-out the mixture to reduce the amout of
: "liquid" collecting on the walls
: * put some heat into the intake manifold
: * "stagger" the jetting, try leaning
: the barrel(s) closest to the rich runners.
: (the outer ones)
:
: You may want to do some adjustments and run the
: car more, then read the plugs again. Try to
: adjust the mixture based on W.O.T. runs on
: the engines and plug readings right after
: those wide open throttle passes.
: DD

: Thanks, Doug. I had unhooked the PCV 2 days
: ago, and cleaned all the spark plugs. I
: checked the plugs again today, and the
: pattern was back, with #6 still being the
: blackest, with #1 not too far behind. I'm
: going to try putting a #65 jet in the outer
: barrel, and leave the #66 in the inner
: barrel. If it needs more, I'll go down to a
: #65/#64 setup. I had thought about drilling
: and tapping a hole on the drivers' side of
: the intake, under the carburetor, to run the
: PCV into, but since it didn't seem to make
: much difference in the plug color, I just
: put it back into the #6 runner.
: How can I get more fuel into #'s 4 and 5? Those
: 2 plugs were clean/white. #2 and 3 look ok.
:
: Someone else had said to lean the INNER barrel,
: but I don't see how that will help.
: Since this car is driven on the street, doing
: WOT runs and reading the plugs will be
: difficult, not to mention not relevant to
: everyday driving. It spends most of its'
: time on the primaries, although I open up
: the 4's whenever possible.
: During some top end runs today, it felt like it
: would run out of fuel around 4000 rpm in
: high gear. Surge,die,surge,die every couple
: of seconds. A new filter didn't help, I
: think it needs a HV fuel pump.

: You are doing all the right stuff, dialing-in a
: new engine combo is like "peeling an
: onion", (eating an artichoke here in
: CA)you have to keep working through issues
: to fine new ones, eventually you get to the
: "real good stuff".
:
: I would get a fuel guage onto the set-up, from
: what you said, it does sound like the fuel
: delivery system is weak. If so, that needs
: to be resolved before you go farther with
: the distribution correction / carb
: adjustments.
:
: Sorry to say that a carb. is never going to get
: you completly even plug color accross all 6.
: That is why everything you see today is
: "dry manifold" with fuel
: injection. I have "maximized" many
: wet manifold set-ups and with a 4 bbl, you
: have to decide if you want best distribution
: with the secondaries open or closed, with
: your "front-back" carb. mounting,
: this will always be a "trade-off"
: situation. You can't get good distribution
: under both conditions. (sorry)For racing, I
: tend to maximuze the distribution with all
: barrels open. (max power) Part throttle
: operation is not as critical.
: Keep working it, more later...
: DD

:
: I took it to the track last night. It needs
: more tuning, and a good fuel pump. Did I
: mention I put a 6.5 power valve in? I did.
: Replaced the stock 8.5 . This engine hot
: idles in gear with 9-10" of vaccum.
: First tank of gas was a horrible 13-14 mpg.
: The fuel system problems kept coming up in
: 2nd gear at high (5000) rpm. I'm sure it
: cost me a tenth or 2. Also need to further
: tune the accelerator pump and jets. I made 4
: runs in the 16.7's and 16.8's at 82 mph.
:
: I thought I read somewhere a while back that if
: you put the /6 fuel pump operating lever in
: a big block / hemi fuel pump, that makes a
: good HV pump for a /6. Will this work? I
: want to buy a new fuel pump as soon as
: possible and get this problem fixed.

: 16.7 is not bad for the first time out, what
: was the 60 ft. time? (the first 60 feet has
: a lot to do with a good ET)
:
: Yes, get a Carter High Volume BB Mopar fuel
: pump and swap-in the arm from a stock SL6
: pump. It is best to shim-out any slack so
: there is constant pump piston movement.
: (don't allow the arm to leave the cam's fuel
: pump lobe, it can "top-out in it's
: travel. You will see what I mean once you
: are in there)
:
: Keep "peeling the artichoke"!
: DD